Many electronic devices communicate with each other using wireless local area networks (WLANs), such as those based on a communication protocol that is compatible with an IEEE 802.11 standard (which is sometimes referred to as ‘Wi-Fi’). For example, in some IEEE 802.11 standards, electronic devices can communicate with each other using a shared band of frequencies that has dual use. In particular, the shared band of frequencies may be used by the electronic devices for wireless communication and, occasionally, by a higher priority user, such as a radar system.
In the event that the higher priority user is using the shared band of frequencies, the electronic devices are typically required to discontinue wireless communication in the shared band of frequencies within a predefined time interval. For example, in the United States, channels in the 5470-5725 MHz band of frequencies are dual use for wireless communication and radar systems. When radar signals are detected, electronic devices that are using the shared channels are required by federal regulations to discontinue use within prescribed time, such as within 200 milliseconds. This shared spectrum technique is referred to as ‘dynamic frequency selection’ (DFS).
In WLANs, DFS is usually implemented by access points that monitor for radar signals and, when the radar signals are detected, that provide instructions to associated electronic devices to discontinue use of the shared band of frequencies, the instructions provided via one or more action frames with channel switch announcements (CSAs) and subsequent beacons that include CSAs. However, many electronic devices may not be able to receive these instructions from an access point. This includes legacy electronic devices, as well as other electronic devices that are not associated with the access point.
Consequently, the legacy electronic devices and the other electronic devices may not be able to use the shared band of frequencies. Instead, the legacy electronic devices and the other electronic devices may use other, more crowded bands of frequencies. The resulting collisions may degrade the communication performance and, thus, may be frustrating to users of the legacy electronic devices and the other electronic devices, which may degrade the user experience.